Thankfully, a University of Washington climate scientist decided to tackle the problem and found out that a romantically dew covered bottle or glass of beer/wine cooler/chilled white wine (etc.) will warm up faster because of the condensation on the bottle.

So, want to keep that bottle cold longer – keep it dry.

[...]

Plenty of examples exist for evaporative cooling, but few for the reverse phenomenon, and Durran thought droplets that form on a cold canned beverage might be just the example he was looking for. A quick back-of-the-napkin calculation showed the heat released by water just four thousandths of an inch thick covering the can would heat its contents by 9 degrees Fahrenheit.
— Science fact: How to keep a bottle of beer cold? Keep it dry

Just as well I drink mostly real ale served at ambient temperature. That said, I think I might need to invest in a stubbie holder for those few ales best served cold.